AB1564 PERIPHERAL BLOOD PERFUSION IN MCTD AND UCTD PATIENTS: A CROSS-SECTIONAL MONOCENTRIC STUDY
Authors: A. Cere, E. Hysa, A. Lercara, A. Pinelli, E. Gotelli, C. Pizzorni, S. Paolino, A. Sulli, V. Smith, M. Cutolo
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Connective tissue diseases (CTDs) are a heterogeneous group of autoimmune disorders and, among them, mixed connective tissue disease (MCTD) and undifferentiated connective tissue disease (UCTD) show overlap symptoms with other CTDs, but share secondary Raynaud's Phenomenon (sRP) as a typical vascular symptom<sup>[1,2]</sup>. Laser speckle contrast analysis (LASCA) is a reliable tool to measure the peripheral blood perfusion (PBP) and has already demonstrated to be useful in detecting the peripheral microcirculation status of SSc patients and severe sRP<sup>[3]</sup>. <h3>Objectives</h3> To measure hand PBP in patients with sRP in CTDs (MCTD, UCTD) and to compare it with healthy controls (HCs). <h3>Methods</h3> Twenty-four CTDs patients with sRP (7 with MCTD, 17 with UCTD) and 28 age- and sex-matched HCs were evaluated during standard follow-up assessments. CTDs diagnoses were set up according to the international classification criteria<sup>[4,5]</sup>. Patients had a stable therapy (mainly glucocorticoids and conventional disease modifying anti-rheumatic drugs) and had not had intravenous vasodilator treatments for the previous three months at least. All subjects underwent a LASCA registration (Laser Speckle Contrast Analysis - Pericam PSI, Perimed, Jarfalla) after acclimatization of 15 minutes at 20-22°C. After recording, PBP was quantified (perfusion units, P.U.) in the following region of interests (ROIs): fingertips (with and without thumbs) and periungual areas (with and without thumbs). Statistical analysis was performed using DATATab®, with parametric tests in case of normally distributed data and non-parametric tests in case of non-symmetrically distributed data. <h3>Results</h3> Although not statistically significant, a trend to a lower PBP was found when comparing MCTD LASCA values versus UCTD LASCA values, particularly for ROIs of periungual areas (see Table 1). In addition, PBP was found significantly lower in MCTD and UCTD when individually compared with HCs. This result was confirmed for all four ROIs (p&lt;0,02; see Table 1). <h3>Conclusion</h3> To our knowledge, no evaluations of PBP by LASCA are available in literature in other CTDs other than SSc<sup>[6]</sup>. This preliminary study showed, using the LASCA methodology, that the PBP in MCTD and UCTD patients affected by sRP is significantly lower than in age- and sex-matched HCs. A trend with a lower PBP in MCTD patients than UCTD patients was observed but did not reach a statistical significance due to the small sample size. These results may demonstrate a potential role of LASCA in assessing the vascular involvement of CTDs other than SSc. Further investigations on a larger and more homogeneous sample size and a focus on the possible correlations between PBP and the morphological microvascular damage assessed by nailfold videocapillaroscopy have been planned. <h3>References</h3> [1]Pauling, J. D. <i>et al.</i>, <i>Clin. Rheumatol.</i>, 2019. [2]Hirschl, M. <i>et al.</i>, <i>Arthritis Rheum.</i>, 2006. [3]Cutolo, M. <i>et al.</i>, <i>Autoimmun. Rev.</i>, 2018. [4]Tani, C. <i>et al.</i>, <i>J. Autoimmun.</i>, 2014. [5]Antunes, M. <i>et al.</i>, <i>RMD Open</i>, 2019. [6]Ruaro, B. <i>et al.</i>, <i>Ann. Rheum. Dis.</i>, 2014. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.